Resounding Celtic Sapphire
Resounding Celtic Sapphire (#296FF3) is a true azure with a neon character. It sits at the high-saturation edge of its family. Use it sparingly, as signage, accent, or highlight against darker surfaces. Its HSL profile (219°, 89%, 56%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. For a confident two-color system, pair it with its complementary amber. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin resonāre, to echo back — present-participle of resound. As a color modifier, resounding implies a saturated-and-echoing-and-imposing quality where the hue reverberates visually like a cathedral-bell ring. Sits at the bold-and-resonant end of the grid, parallel to resonant and booming in usage.
Latin Celticus, of-the-Celts. As a color modifier, celtic implies a knotwork-and-La-Tène quality, the visual register of Irish-and-Welsh-and-Scottish Celtic-knotwork hand-carved bronze-and-stone metalwork-and-illuminated-manuscript surfaces under Celtic-Irish-Welsh-Scottish illuminated-manuscript-tradition light. Sits at the modifier-and-cultural end of the grid, parallel to norse and welsh in usage.
An iron-and-titanium-bearing corundum — the same mineral as ruby, hardness 9 on the Mohs scale, mined for two millennia from Sri Lanka, Burma, Madagascar, and the Cashmere mines of British India. The color refers to a fine Kashmir-cut sapphire: a saturated, slightly violet-shifted deep blue with the gem's signature internal velvet — a quality of light scattering in the stone that faceted glass cannot replicate. Cooler than cobalt, deeper than azure.
Closest matches
The nearest named color in three reference sources, ranked by perceptual distance (ΔE76 in CIELAB). ΔE < 1 is imperceptible to most viewers; ΔE > 10 is clearly different. When two sources point to the same hex they’re merged into one tile; click any to open that color’s page.
Variations
Click any swatch to exploreHarmonies
Accessibility
How this color appears to viewers with the four major color-vision-deficiency types. Computed via the Machado (2009) physiologically-based model. If a tile matches the original, the color reads the same to that viewer.
The color used as foreground text against pure white and pure black, with the contrast ratio and WCAG 2.1 grade. Aim for AA (4.5:1) for body text and AA Large (3:1) for 18 pt+ headlines; AAA (7:1) is the gold standard for long-form reading surfaces.